That's about 46 million smokers in the US – or 20.6 percent of the adult population. Every day, 1,000 young people become new smokers, the CDC says. (The level in 2004 was 20.9 percent, dipping to 19.7 in 2007.)

Cigarette smoking also varies by race, gender, and education level. Less than 10 percent of Asian-Americans smoke, but native Americans and Alaska natives have rates three times higher. Gender also plays a role, with 23 percent of all men smoking, compared with 18 percent of all women. Smoking levels are also lower for those who have a college education compared with those who don't.